1. Field of the Invention
The present invention relates to an electrical connector and more particularly, to an electrical connector mounted on a printed circuit board or the like.
2. Description of the Prior Art
Electrical connectors are usually mounted on a printed circuit board as a component of a contact device, as disclosed in U.S. Pat. No. 5,727,954 issued to Kato on Mar. 17, 1998. In this patent, the Kato connector is of a two-part construction vertically defining a plurality of through holes. A plurality of terminals received in the through holes and each include an upper terminal normally upwardly projecting beyond a corresponding through hole, a lower terminal apart from the upper terminal and normally downwardly projecting beyond the through hole and a middle spring compressed between the upper terminal and the lower terminal. The upper terminal and the lower terminal have opposite wedge-shaped ends. The ends are inserted into opposite upper and lower coiled hollows of the spring respectively. The assembled terminal is held in the through hole such that the terminal as a whole can be axially movable relative to the assembled housing. In use, a mating electrical device (battery, memory card or printed circuit board etc.) depresses and electrically connects the upper terminal. The upper terminal electrically connects with the lower terminal via the spring positioned therebetween. The lower terminal is electrically contacted under pressure with a wiring substrate, thereby the mating device electrically connects with the wiring substrate via the electrical connector.
However, the spring may be invalidated such as distortion and resilient less after a period of use. Furthermore, the opposite wedge-shaped ends of the upper terminal and the lower terminal are inclined to get away from the coiled hollows of the invalid spring, resulting in an unreliable connection between the upper and the lower terminals. As a result, the electrical connector cannot reliably interconnect the mating device with the wiring substrate.
Hence, an improved electrical connector is needed to overcome the foregoing shortcomings.